Hanna is a geek in Sweden. I don't know her, I don't know of her. She's not a huge name as far as I can tell.
But she just did something amazing using Twitter and Spotify. About an hour ago she created a collaborative playlist on Spotify and tweeted the playlist link asking for Christmas songs.

One hour ago. The playlist is now 18 songs and 1.2 hours long. Potentially it could last forever if more people join in.

Thanks Hanna, for showing us a great example of the power of social media and crowd sourcing.